We are commanded to circumcise male children on the eighth day after they are born [as it says "And on the eighth day the flesh of his foreskin shall be circumcised"].¹ Circumcision was the basis of G-d's covenant with Abraham, as it says "And I will make my covenant between Me and you... [you shall circumcise the flesh of your foreskin and it shall be a sign of a covenant between Me and you; every male of all your generations shall be circumcised at the age of eight days...]".² The responsibility rests on the father; if he does not do it the courts are responsible; and when the child grows up the responsibility devolves on him.^a If the child is not well his circumcision is postponed until he recovers.^b Circumcision consists of cutting away the foreskin and peeling off the membrane under it.^c

Sources:
1. Lev. 12:3	a. 1:1-2, 3:8
2. Gen. 17:2,11-12	b. 1:16
	c. 2:2